Methods and apparatuses for encoding and decoding video using periodic buffer description

ABSTRACT

A method of encoding video including: writing a plurality of predetermined buffer descriptions into a sequence parameter set of a coded video bitstream; writing a plurality of updating parameters into a slice header of the coded video bitstream for selecting and modifying one buffer description out of the plurality of buffer descriptions; and encoding a slice into the coded video bitstream using the slice header and the modified buffer description.

TECHNICAL FIELD

This invention can be used in any multimedia data coding and, moreparticularly, in coding of image and video contents utilizinginter-picture prediction.

BACKGROUND ART

State-of-the-art video coding schemes, such as MPEG-4 AVC/H.264 and theupcoming HEVC (High-Efficiency Video Coding), perform coding ofimage/video content using inter-picture prediction from previouslycoded/decoded reference pictures, to exploit the information redundancyacross consecutive pictures in time. In MPEG-4 AVC video coding scheme,reference pictures in the decoded picture buffer (DPB) are managedeither using a predefined sliding-window scheme for removing earlierpictures in coding order from the DPB, or explicitly using a number ofbuffer management signals in the coded video bitstream to manage andremove unused reference pictures.

Recent developments in the HEVC video coding scheme include theintroduction of DPB management using buffer descriptions. Essentially, abuffer description defines the pictures that are retained/included inthe DPB instead of defining the pictures to be removed from the DPB. Abuffer description is a list of unique picture identifiers indicatingall reference pictures that are stored in the DPB. A buffer descriptionis activated at the start of encoding/decoding of a picture. Picturesthat are not included in the active buffer description are removed fromthe DPB. Benefits of buffer descriptions over conventional methodsinclude improved robustness against transmission/delivery losses andsimplified handling of non-existent pictures.

Picture referencing structures are often repeated across multiplepictures in a coded video sequence. For example, a low delay codingstructure may use a periodic clustering of size four as shown in FIG. 1.

In this example, the picture numbers (0 to 12) indicates both codingorder and display/output order of pictures. The pictures P0, P4, P8 andP12 constitute the first temporal layer of pictures and are coded withthe highest quality (for example by applying quantization leaststrongly). Pictures P2, P6 and P10 constitute the second temporal layerand are coded with lower quality than the first layer. Picture P1, P3,P5, P7, P9 and P11 constitutes the third temporal layer and are codedwith the lowest quality. In such a periodic clustering structure,pictures the located at the same relative position within their clusters(for example P1, P5 and P9) usually use the same relative picturereferencing structure. For example, P5 uses P4 and P2 as referencepictures, while P9 uses P8 and P6 as reference pictures.

In order to accommodate periodic clustering structures such as the aboveexemplary structure, periodic signaling of buffer descriptions wasintroduced. A periodic buffer description lists the reference picturesstored in the DPB by specifying the temporal distances/positions of thereference pictures relative to a target picture to be encoded/decoded.In the prior art, a periodic buffer description is signaled once in thepicture parameter set (PPS), and then referred to repeatedly in theslice headers of the pictures having the same relative position within aperiodic cluster. For example, a periodic buffer description specifyingrelative positions of {−1, −3} can be used in both P5 to specify {P4,P2} as reference pictures and by P9 to specify {P8, P6} as referencepictures.

FIG. 2 shows an example of the signaling structure of periodic bufferdescription in the prior art. A plurality of periodic bufferdescriptions are specified in the picture parameter sets. Each PPS isidentified by a unique “PPS_id” parameter. In a slice header, a “PPSselect” parameter identifies the PPS referred to duringencoding/decoding of the slice. In the example in FIG. 2, the PPS havingPPS_id=0 is selected. A plurality of “BD updating” parameters selects aperiodic buffer description out of the predefined buffer descriptions.In the example in FIG. 2, the buffer description BD1 is selected.Additionally, “BD updating” parameters also includes a bufferdescription modification command. The buffer modification commandsassign a picture identifier to a selected buffer element within theselected buffer description. A unique/absolute picture identifier isspecified here instead of a relative picture identifier. In the examplein FIG. 2, the unique picture P_(G) is assigned to the buffer elementBE0 within the buffer description BD1. This modification applies only tothe current target slice. To use the same modification in subsequentslices, the slice headers of those subsequent slices shall specify “BDupdating” parameters accordingly.

SUMMARY OF INVENTION Technical Problem

One problem with the prior art of periodic buffer description is thatthe parameters for modifying a periodic buffer description are onlyapplied once (that is, applied in a current slice to beencoded/decoded). Consequently, the same modification needs to besignaled multiple times in order to use it more than once.

Another problem with the prior art is that the parameters for creatingperiodic buffer descriptions are signaled in the picture parameter set(PPS). However, a periodic picture clustering structure is usually usedover a large number of pictures and often over an entire coded videosequence. Therefore, the same parameters may be signaled repeatedly inmultiple picture parameter sets throughout the coded video sequence.Such repeated signaling occupies bits unnecessarily in the coded videobitstream.

Solution to Problem

To solve the above problems, the present invention introduces newmethods and apparatuses for signaling periodic buffer descriptions in acoded video bitstream.

What is novel about this invention is that it provides a means to createand modify periodic buffer descriptions in a hierarchical manner,thereby achieving improved harmonization with the hierarchicallystructured signaling units (such as the Network Abstraction Layer units)in a coded video bitstream.

Advantageous Effects of Invention

The effect of the present invention is in the form of coding efficiencyimprovement of buffer description data in a coded video bitstream and inthe form of design harmonization of buffer description data units withhierarchically structured signaling units in a coded video bitstream.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an example of a picture referencing structure.

FIG. 2 is a diagram showing locations of the parameters for creating andmodifying buffer descriptions in a coded video bitstream according tothe prior art.

FIG. 3 is a block diagram showing a structure of video/image encodingapparatus in the present invention.

FIG. 4 is a flowchart showing a picture encoding process according tothe first embodiment of the present invention.

FIG. 5A is a syntax diagram showing the locations of the parameters forcreating and modifying buffer descriptions in a coded video bitstream inexample embodiments of the first embodiment of the present invention.

FIG. 5B is a syntax diagram showing the locations of the parameters forcreating and modifying buffer descriptions in a coded video bitstream inexample embodiments of the first embodiment of the present invention.

FIG. 6 is a block diagram showing a structure of video/image decodingapparatus in the present invention.

FIG. 7 is a flowchart showing a picture decoding process according tothe first embodiment of the present invention.

FIG. 8 is a flowchart showing a picture encoding process according tothe second embodiment of the present invention.

FIG. 9A is a syntax diagram showing the locations of the parameters forcreating and modifying buffer descriptions in a coded video bitstream inexample embodiments of the second embodiment of the present invention.

FIG. 9B is a syntax diagram showing the locations of the parameters forcreating and modifying buffer descriptions in a coded video bitstream inexample embodiments of the second embodiment of the present invention.

FIG. 10 is a flowchart showing a picture decoding process according tothe second embodiment of the present invention.

FIG. 11 is a flowchart showing a picture encoding process according tothe third embodiment of the present invention.

FIG. 12A is a tables showing the example locations of bufferdescriptions in SPS.

FIG. 12B is a tables showing the example locations of updatingparameters for selecting and modifying a buffer description in sliceheader.

FIG. 12C is a tables showing the example locations of updatingparameters for selecting and modifying a buffer description in sliceheader.

FIG. 13 is a syntax diagram showing the locations of the parameters forcreating and modifying buffer descriptions in a coded video bitstream inexample embodiments of the third embodiment of the present invention.

FIG. 14 is a flowchart showing a picture decoding process according tothe third embodiment of the present invention.

FIG. 15 shows an overall configuration of a content providing system forimplementing content distribution services.

FIG. 16 shows an overall configuration of a digital broadcasting system.

FIG. 17 shows a block diagram illustrating an example of a configurationof a television.

FIG. 18 shows a block diagram illustrating an example of a configurationof an information reproducing/recording unit that reads and writesinformation from and on a recording medium that is an optical disk.

FIG. 19 shows an example of a configuration of a recording medium thatis an optical disk.

FIG. 20A shows an example of a cellular phone.

FIG. 20B is a block diagram showing an example of a configuration of acellular phone.

FIG. 21 illustrates a structure of multiplexed data.

FIG. 22 schematically shows how each stream is multiplexed inmultiplexed data.

FIG. 23 shows how a video stream is stored in a stream of PES packets inmore detail.

FIG. 24 shows a structure of TS packets and source packets in themultiplexed data.

FIG. 25 shows a data structure of a PMT.

FIG. 26 shows an internal structure of multiplexed data information.

FIG. 27 shows an internal structure of stream attribute information.

FIG. 28 shows steps for identifying video data.

FIG. 29 shows an example of a configuration of an integrated circuit forimplementing the moving picture coding method and the moving picturedecoding method according to each of embodiments.

FIG. 30 shows a configuration for switching between driving frequencies.

FIG. 31 shows steps for identifying video data and switching betweendriving frequencies.

FIG. 32 shows an example of a look-up table in which video datastandards are associated with driving frequencies.

FIG. 33A is a diagram showing an example of a configuration for sharinga module of a signal processing unit.

FIG. 33B is a diagram showing another example of a configuration forsharing a module of the signal processing unit.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an image decoding apparatus and an image coding apparatusaccording to an aspect of the present invention shall be described withreference to the drawings.

It is to be noted that the embodiments described below shows a specificexample of the present invention. The numerical values, shapes,materials, structural elements, the arrangement and connection of thestructural elements, steps, the processing order of the steps etc. shownin the following exemplary embodiments are mere examples. Therefore,among the structural elements in the following exemplary embodiments,structural elements not recited in any one of the independent claimsdefining the most generic part of the inventive concept are described asarbitrary structural elements.

Three embodiments of the present invention are described in thefollowing. It will be apparent to those skilled in the art thatcombinations of the embodiments can be carried out to further increasethe adaptability and flexibility of periodic buffer descriptions.

Embodiment 1

(Encoding Apparatus)

FIG. 3 is a block diagram which shows a structure of video/imageencoding apparatus 200 in the present invention.

The video encoding apparatus 200 is an apparatus for encoding an inputvideo/image bit stream on a block-by-block basis so as to generate anencoded output bit stream. As shown in FIG. 3, a transformation unit201, a quantization unit 202, an inverse quantization unit 203, aninverse transformation unit 204, a block memory 205, a frame memory 206,an intra prediction unit 207, an inter prediction unit 208, an entropycoding unit 209, a frame memory control unit 210.

An input video is inputted to an adder, and the added value is outputtedto the transformation unit 201. The transformation unit 201 transformsthe added values into frequency coefficients, and outputs the resultingfrequency coefficients to the quantization unit 202. The quantizationunit 202 quantizes the inputted frequency coefficients, and outputs theresulting quantized values to the inverse quantization unit 203 and theentropy coding unit 209. The entropy coding unit 209 encodes thequantized values outputted from the quantization unit 202, and outputs abit stream.

The inverse quantization unit 203 inversely quantizes the sample valuesoutputted from the quantization unit 202, and outputs the frequencycoefficients to the inverse transformation unit 204. The inversetransformation unit 204 performs inverse frequency transform on thefrequency coefficients so as to transform the frequency coefficientsinto sample values of the bit stream, and outputs the resulting samplevalues to an adder. The adder adds the sample values of the bit streamoutputted from the inverse transformation unit 204 to the predictedvideo/image values outputted from the inter/intra prediction unit 207,208, and outputs the resulting added values to the block memory 205 orthe frame memory 206 (through the frame memory control unit 210) forfurther prediction. The inter/intra prediction unit 207, 208 searcheswithin reconstructed videos/images stored in the block memory 205 or theframe memory 206, and estimates a video/image area which is e.g. mostsimilar to the input videos/images for prediction.

The frame memory control unit 210 manages the reconstructed picturesstored in the frame memory 206. It also sends frame memory controlparameters to be written by the entropy coding unit 209 into the outputbitstream.

(Encoding Process)

FIG. 4 is a flowchart which shows a picture encoding process 400according to the first embodiment of the present invention.

Step 401 determines a plurality of predetermined periodic bufferdescriptions to be used over a plurality of pictures in a coded videosequence. Step 402 then writes said plurality of buffer descriptionsinto a sequence parameter set of a coded video bitstream. Next, Step 403determines a plurality of modifications to be performed for a subset ofbuffer descriptions out of said plurality of buffer descriptions. Step404 then writes a plurality of updating parameters into a pictureparameter set of said coded video bitstream for performing saidmodifications for said subset of buffer descriptions. During theencoding of a target picture, Step 405 writes a buffer descriptionidentifier into a header of said target picture in said coded videobitstream for selecting one buffer description out of said plurality ofmodified buffer descriptions. Step 406 then encodes said target pictureinto said coded video bitstream using said picture parameter set andsaid selected buffer description.

Said updating parameters written in Step 404 comprise a bufferdescription identifier for selecting a buffer description, a bufferelement identified for selecting a buffer element within said selectedbuffer description, and a picture identifier for reassigning a uniquereference picture to be associated with said selected buffer elementwithin said selected buffer description. A buffer description consistsof a plurality of buffer elements, where each buffer element correspondsto a unique reference picture stored in the frame memory.

Said updating parameters written in Step 404 may additionally comprise aflag/parameter to indicate that buffer description modifications are notperformed and that said buffer descriptions defined in sequenceparameter set remains are they are. When multiple picture parameter setsare present in said coded video bitstream, buffer descriptionmodifications specified in different picture parameter sets areindependent of each other. That is, the modifications specified in afirst picture parameter set are not applied when a second pictureparameter set is active (in use), and the modifications specified insaid active second picture parameter set are applied on top of theinitial buffer descriptions defined in the sequence parameter set.

Said updating parameters written in Step 404 comprise a plurality ofparameters to create/define new additional buffer descriptions inaddition to the plurality of buffer descriptions defined in the sequenceparameter set.

In a possible implementation of the present invention, said sequenceparameter set written in Step 402 comprises a flag to indicate whetheror not said plurality of buffer description is present in said sequenceparameter set. When buffer descriptions are not present in said sequenceparameter set, said updating parameters in said picture parameter setcomprise a plurality of parameters for creating one or more bufferdescriptions.

(Effect of Encoding Invention)

The effect of the present invention is in the form of coding efficiencyimprovement of buffer description data in a coded video bitstream and inthe form of design harmonization of buffer description data units withhierarchically structured signaling units in a coded video bitstream.Using the present invention, redundant repetition of the same parametersin a coded video bitstream for creating and modifying periodic bufferdescriptions are removed.

(Syntax Diagram)

FIGS. 5A and 5B are each syntax diagram which shows locations of theparameters for creating and modifying buffer descriptions in a codedvideo bitstream in example embodiments of the present invention.

In FIG. 5A, parameters for defining/creating a plurality of bufferdescriptions are located in a sequence parameter set. A sequenceparameter set is referred by a picture parameter set using a uniqueSPS_id parameter. Parameters for updating said plurality of bufferdescriptions are located in a picture parameter set. In a picture headerof a coded picture, a picture parameter set is referred using a uniquePPS_id parameter. A picture consists of a picture header and one or moreslices (or sub-pictures). A buffer description selecting parameter forselecting one buffer description out of the plurality of modified bufferdescriptions is located in said picture header of said coded picture.

In FIG. 5B, parameters for defining/creating a plurality of bufferdescriptions are located in a sequence parameter set. A sequenceparameter set is referred by a picture parameter set using a uniqueSPS_id parameter. Parameters for updating said plurality of bufferdescriptions are located in a picture parameter set. In a slice header(or sub-picture unit header) of a coded slice (or sub-picture unit), apicture parameter set is referred using a unique PPS_id parameter. Abuffer description selecting parameter for selecting one out of theplurality of modified buffer descriptions is located in said sliceheader (or sub-picture unit header).

In possible implementations of the present invention, examples of asub-picture unit include a tile, an entropy slice, and a group of blocksconstituting a wavefront processing sub-picture partition.

(Decoding Apparatus)

FIG. 6 is a block diagram which shows a structure of video decodingapparatus 300 in the present invention.

The video decoding apparatus 300 is an apparatus for decoding an inputcoded bit stream on a block-by-block basis and outputting videos/images,and comprises as shown in FIG. 6, an entropy decoding unit 301, aninverse quantization unit 302, an inverse transformation unit 303, ablock memory 304, a frame memory 305, an intra prediction unit 306, aninter prediction unit 307, a frame memory control unit 308.

An input encoded bit stream is inputted to the entropy decoding unit301. After the input encoded bit stream is inputted to the entropydecoding unit 301, the entropy decoding unit 301 decodes the inputencoded bit stream, and outputs the decoded values to the inversequantization unit 302. The inverse quantization unit 302 inverselyquantizes the decoded values, and outputs the frequency coefficients tothe inverse transformation unit 303. The inverse transformation unit 303performs inverse frequency transform on the frequency coefficients totransform the frequency coefficients into sample values, and outputs theresulting pixel values to an adder. The adder adds the resulting pixelvalues to the predicted video/image values outputted from theintra/inter prediction unit 306, 307, and outputs the resulting valuesto display, and outputs the resulting values to the block memory 304 orthe frame memory 305 (through the frame memory control unit 308) forfurther prediction. In addition, the intra/inter prediction unit 306,307 searches within videos/images stored in the block memory 304 orframe memory 305, and estimates a video/image area which is e.g. mostsimilar to the decoded videos/images for prediction.

The frame memory control unit 308 manages the reconstructed picturesstored in the frame memory 305. It reads frame memory control parametersfrom the entropy decoding unit 301 and performs memory controloperations accordingly.

(Decoding Process)

FIG. 7 is a flowchart which shows a picture decoding process 500according to the first embodiment of the present invention.

Step 501 parses a plurality of buffer descriptions from a sequenceparameter set of a coded video bitstream. Next, Step 502 parses aplurality of updating parameters from a picture parameter set of saidcoded video bitstream for modifying a subset of buffer descriptions outof said plurality of buffer descriptions. Step 503 then parses a bufferdescription identifier from a header of a picture in said coded videobitstream for selecting one buffer description out of said plurality ofmodified buffer descriptions. Finally, Step 504 decodes said picturefrom said coded video bitstream using said picture parameter set andsaid selected buffer description.

(Effects of Decoding Invention)

The effect of the present invention is to enable the decoding of a codedvideo bitstream which is coded in the form of improved coding efficiencyand harmonized design of buffer description data.

Embodiment 2

(Encoding Apparatus)

FIG. 3 is a block diagram which shows a structure of video/imageencoding apparatus 200 in the present invention.

The video encoding apparatus 200 is an apparatus for encoding an inputvideo/image bit stream on a block-by-block basis so as to generate anencoded output bit stream. As shown in FIG. 3, a transformation unit201, a quantization unit 202, an inverse quantization unit 203, aninverse transformation unit 204, a block memory 205, a frame memory 206,an intra prediction unit 207, an inter prediction unit 208, an entropycoding unit 209, a frame memory control unit 210.

An input video is inputted to an adder, and the added value is outputtedto the transformation unit 201. The transformation unit 201 transformsthe added values into frequency coefficients, and outputs the resultingfrequency coefficients to the quantization unit 202. The quantizationunit 202 quantizes the inputted frequency coefficients, and outputs theresulting quantized values to the inverse quantization unit 203 and theentropy coding unit 209. The entropy coding unit 209 encodes thequantized values outputted from the quantization unit 202, and outputs abit stream.

The inverse quantization unit 203 inversely quantizes the sample valuesoutputted from the quantization unit 202, and outputs the frequencycoefficients to the inverse transformation unit 204. The inversetransformation unit 204 performs inverse frequency transform on thefrequency coefficients so as to transform the frequency coefficientsinto sample values of the bit stream, and outputs the resulting samplevalues to an adder. The adder adds the sample values of the bit streamoutputted from the inverse transformation unit 204 to the predictedvideo/image values outputted from the inter/intra prediction unit 207,208, and outputs the resulting added values to the block memory 205 orthe frame memory 206 (through the frame memory control unit 210) forfurther prediction. The inter/intra prediction unit 207, 208 searcheswithin reconstructed videos/images stored in the block memory 205 or theframe memory 206, and estimates a video/image area which is e.g. mostsimilar to the input videos/images for prediction.

The frame memory control unit 210 manages the reconstructed picturesstored in the frame memory 206. It also sends frame memory controlparameters to be written by the entropy coding unit 209 into the outputbitstream.

(Encoding Process)

FIG. 8 is a flowchart which shows a picture encoding process 600according to the second embodiment of the present invention.

Step 601 determines a plurality of predetermined periodic bufferdescriptions to be used over a plurality of pictures in a coded videosequence. Step 602 then writes said plurality of buffer descriptionsinto a sequence parameter set of a coded video bitstream. Next, Step 603selects one buffer description out of said plurality of bufferdescriptions and determines a plurality of modifications to be performedon said selected buffer description. Step 604 then writes a plurality ofupdating parameters into a picture parameter set of said coded videobitstream for selecting and modifying said selected buffer description.Finally, Step 605 encodes one or a plurality of target pictures intosaid coded video bitstream using said picture parameter set and saidmodified buffer description.

Said updating parameters written into a picture parameter set in Step604 comprise a buffer description identifier for selecting a bufferdescription, a buffer element identified for selecting a buffer elementwithin said selected buffer description, and a picture identifier forreassigning a unique reference picture to be associated with saidselected buffer element within said selected buffer description. Abuffer description consists of a plurality of buffer elements, whereeach buffer element corresponds to a unique reference picture stored inthe frame memory.

Said updating parameters written into a picture parameter set in Step604 may additionally comprise a flag/parameter to indicate whether ornot a selected buffer description is modified. When the flag indicatesthat a selected buffer description is not modified, said selected bufferdescription is used according to its initial definition in sequenceparameter set. According to the second embodiment of the presentinvention, said updating parameters in said picture parameter set (Step604) selects and modifies only one buffer description out of saidplurality of buffer descriptions defined in the sequence parameter set.

When multiple picture parameter sets are present in said coded videobitstream, buffer description modifications specified in differentpicture parameter sets are independent of each other. That is, differentpicture parameter sets may select different buffer description;furthermore, the modifications specified in a first picture parameterset are not applied when a second picture parameter set is active (inuse), and the modifications specified in said active second pictureparameter set are applied on top of the initial buffer descriptionsdefined in the sequence parameter set.

In a possible implementation of the present invention, said sequenceparameter set written in Step 602 comprises a flag to indicate whetheror not said plurality of buffer description is present in said sequenceparameter set. When buffer descriptions are not present in said sequenceparameter set, said updating parameters in a picture parameter setcomprise a plurality of parameters for creating a buffer description.

(Effect of Encoding Invention)

The effect of the present invention is in the form of coding efficiencyimprovement of buffer description data in a coded video bitstream and inthe form of design harmonization of buffer description data units withhierarchically structured signaling units in a coded video bitstream.Using the present invention, redundant repetition of the same parametersin a coded video bitstream for creating and modifying periodic bufferdescriptions are removed.

(Syntax Diagram)

FIGS. 9A and 9B are each a syntax diagram which shows locations of theparameters for creating and modifying buffer descriptions in a codedvideo bitstream in example embodiments of the present invention.

In FIG. 9A, parameters for defining/creating a plurality of bufferdescriptions are located in a sequence parameter set. A sequenceparameter set is referred by a picture parameter set using a uniqueSPS_id parameter. Parameters for selecting and modifying one bufferdescription out of said plurality of buffer descriptions are located ina picture parameter set. In a picture header, a picture parameter set isreferred using a unique PPS_id parameter. A plurality of picturescomprising a plurality of slices (or sub-picture units) may refer to thesame picture parameter set associated with a unique PPS_id value. When apicture parameter set is referred in a picture header, the bufferdescription that is selected and modified by said referred pictureparameter set becomes active (in use).

In FIG. 9B, parameters for defining/creating a plurality of bufferdescriptions are located in a sequence parameter set. A sequenceparameter set is referred by a picture parameter set using a uniqueSPS_id parameter. Parameters for selecting and modifying one bufferdescription out of said plurality of buffer descriptions are located ina picture parameter set. In a slice header (or sub-picture unit header)of a coded slice (or sub-picture unit), a picture parameter set isreferred using a unique PPS_id parameter. A plurality of slices mayrefer to the same picture parameter set associated with a unique PPS_idvalue. When a picture parameter set is referred in a slice header, thebuffer description that is selected and modified by said referredpicture parameter set becomes active (in use).

In possible implementations of the present invention, examples of asub-picture unit include a tile, an entropy slice, and a group of blocksconstituting a wavefront processing sub-picture partition.

(Decoding Apparatus)

FIG. 6 is a block diagram which shows a structure of video decodingapparatus 300 in the present invention.

The video decoding apparatus 300 is an apparatus for decoding an inputcoded bit stream on a block-by-block basis and outputting videos/images,and comprises as shown in FIG. 6, an entropy decoding unit 301, aninverse quantization unit 302, an inverse transformation unit 303, ablock memory 304, a frame memory 305, an intra prediction unit 306, aninter prediction unit 307, a frame memory control unit 308.

An input encoded bit stream is inputted to the entropy decoding unit301. After the input encoded bit stream is inputted to the entropydecoding unit 301, the entropy decoding unit 301 decodes the inputencoded bit stream, and outputs the decoded values to the inversequantization unit 302. The inverse quantization unit 302 inverselyquantizes the decoded values, and outputs the frequency coefficients tothe inverse transformation unit 303. The inverse transformation unit 303performs inverse frequency transform on the frequency coefficients totransform the frequency coefficients into sample values, and outputs theresulting pixel values to an adder. The adder adds the resulting pixelvalues to the predicted video/image values outputted from theintra/inter prediction unit 306, 307, and outputs the resulting valuesto display, and outputs the resulting values to the block memory 304 orthe frame memory 305 (through the frame memory control unit 308) forfurther prediction. In addition, the intra/inter prediction unit 306,307 searches within videos/images stored in the block memory 304 orframe memory 305, and estimates a video/image area which is e.g. mostsimilar to the decoded videos/images for prediction.

The frame memory control unit 308 manages the reconstructed picturesstored in the frame memory 305. It reads frame memory control parametersfrom the entropy decoding unit 301 and performs memory controloperations accordingly.

(Decoding Process)

FIG. 10 is a flowchart which shows a picture decoding process 700according to the second embodiment of the present invention.

Step 701 parses a plurality of buffer descriptions from a sequenceparameter set of a coded video bitstream. Next, Step 702 parses aplurality of updating parameters from a picture parameter set of saidcoded video bitstream for selecting and modifying one buffer descriptionout of said plurality of buffer descriptions. Step 703 decodes one or aplurality of pictures from said coded video bitstream using said pictureparameter set and said modified buffer description.

(Effects of Decoding Invention)

The effect of the present invention is to enable the decoding of a codedvideo bitstream which is coded in the form of improved coding efficiencyand harmonized design of buffer description data.

Embodiment 3

(Encoding Apparatus)

FIG. 3 is a block diagram which shows a structure of video/imageencoding apparatus 200 in the present invention.

The video encoding apparatus 200 is an apparatus for encoding an inputvideo/image bit stream on a block-by-block basis so as to generate anencoded output bit stream. As shown in FIG. 3, a transformation unit201, a quantization unit 202, an inverse quantization unit 203, aninverse transformation unit 204, a block memory 205, a frame memory 206,an intra prediction unit 207, an inter prediction unit 208, an entropycoding unit 209, a frame memory control unit 210.

An input video is inputted to an adder, and the added value is outputtedto the transformation unit 201. The transformation unit 201 transformsthe added values into frequency coefficients, and outputs the resultingfrequency coefficients to the quantization unit 202. The quantizationunit 202 quantizes the inputted frequency coefficients, and outputs theresulting quantized values to the inverse quantization unit 203 and theentropy coding unit 209. The entropy coding unit 209 encodes thequantized values outputted from the quantization unit 202, and outputs abit stream.

The inverse quantization unit 203 inversely quantizes the sample valuesoutputted from the quantization unit 202, and outputs the frequencycoefficients to the inverse transformation unit 204. The inversetransformation unit 204 performs inverse frequency transform on thefrequency coefficients so as to transform the frequency coefficientsinto sample values of the bit stream, and outputs the resulting samplevalues to an adder. The adder adds the sample values of the bit streamoutputted from the inverse transformation unit 204 to the predictedvideo/image values outputted from the inter/intra prediction unit 207,208, and outputs the resulting added values to the block memory 205 orthe frame memory 206 (through the frame memory control unit 210) forfurther prediction. The inter/intra prediction unit 207, 208 searcheswithin reconstructed videos/images stored in the block memory 205 or theframe memory 206, and estimates a video/image area which is e.g. mostsimilar to the input videos/images for prediction.

The frame memory control unit 210 manages the reconstructed picturesstored in the frame memory 206. It also sends frame memory controlparameters to be written by the entropy coding unit 209 into the outputbitstream.

(Encoding Process)

FIG. 11 is a flowchart which shows a picture encoding process 800according to the third embodiment of the present invention.

Step 801 determines a plurality of predetermined periodic bufferdescriptions to be used over a plurality of pictures in a coded videosequence. Step 802 then writes said plurality of buffer descriptions(e.g. 1300 of FIG. 12A) into a sequence parameter set of a coded videobitstream. A buffer description is an absolute description of thereference pictures (stored in a buffer) used in the decoding process ofthe current and future coded pictures. An another possible name forbuffer description is reference picture set (RPS). Next, Step 803selects one buffer description (RPS) out of said plurality of bufferdescriptions (RPSs) and determines a plurality of modifications to beperformed on said selected buffer description. Step 804 then writes aplurality of updating parameters (e.g. 1302, 1304 and 1308 of FIG. 12Band FIG. 12C) into a slice header of said coded video bitstream forselecting and modifying said selected buffer description. Finally, Step805 encodes a slice into said coded video bitstream using said sliceheader and said modified buffer description.

Said updating parameters written into a slice header in Step 804comprise a buffer description identifier (1304 of FIG. 12C) forselecting a buffer description, a buffer element identifier forselecting a buffer element within said selected buffer description, anda picture identifier (1308 of FIG. 12C) for reassigning a uniquereference picture to be associated with said selected buffer elementwithin said selected buffer description. A buffer description consistsof a plurality of buffer elements, where each buffer element correspondsto a unique reference picture stored in the frame memory.

Said updating parameters written into a slice header in Step 804 mayadditionally comprise a flag/parameter (1302 of FIG. 12B) to indicatewhether or not a selected buffer description is modified. When the flagindicates that a selected buffer description is not modified, saidselected buffer description is used according to its initial definitionin sequence parameter set. According to the third embodiment of thepresent invention, said updating parameters in said slice header (Step804) selects and modifies only one buffer description out of saidplurality of buffer descriptions defined in the sequence parameter set.

The buffer description modifications specified in different sliceheaders are independent of each other. That is, the modificationsspecified in a slice header only apply to the encoding/decoding of theassociated slice and do not apply to any other slices; furthermore, themodifications specified in each slice header active are applied on topof the initial buffer descriptions defined in the sequence parameterset.

In a possible implementation of the present invention, said sequenceparameter set written in Step 802 comprises a flag (e.g. 1312 of FIG.12A) to indicate whether or not said plurality of buffer description ispresent in said sequence parameter set. When buffer descriptions are notpresent in said sequence parameter set, said updating parameters in aslice header comprise a plurality of parameters for creating a bufferdescription (e.g. 1310 of FIG. 12C).

(Effect of Encoding Invention)

The effect of the present invention is in the form of coding efficiencyimprovement of buffer description data in a coded video bitstream and inthe form of design harmonization of buffer description data units withhierarchically structured signaling units in a coded video bitstream.Using the present invention, redundant repetition of the same parametersin a coded video bitstream for creating and modifying periodic bufferdescriptions are removed.

(Syntax Diagram)

FIG. 13 is a syntax diagram which shows locations of the parameters forcreating and modifying buffer descriptions in a coded video bitstream inexample embodiments of the present invention.

In FIG. 13, parameters for defining/creating a plurality of bufferdescriptions are located in a sequence parameter set. A sequenceparameter set is referred by a picture parameter set using a uniqueSPS_id parameter. A picture parameter set and its associated sequenceparameter set is referred by a slice header (or sub-picture unit header)of a coded slice (or sub-picture unit) using a unique PPS_id parameter.Parameters for selecting and modifying one buffer description out ofsaid plurality of buffer descriptions (defined in the associatedsequence parameter set) are located in the slice header (or sub-pictureunit header). In possible implementations of the present invention,examples of a sub-picture unit include a tile, an entropy slice, and agroup of blocks constituting a wavefront processing sub-picturepartition.

(Decoding Apparatus)

FIG. 6 is a block diagram which shows a structure of video decodingapparatus 300 in the present invention.

The video decoding apparatus 300 is an apparatus for decoding an inputcoded bit stream on a block-by-block basis and outputting videos/images,and comprises as shown in FIG. 6, an entropy decoding unit 301, aninverse quantization unit 302, an inverse transformation unit 303, ablock memory 304, a frame memory 305, an intra prediction unit 306, aninter prediction unit 307, a frame memory control unit 308.

An input encoded bit stream is inputted to the entropy decoding unit301. After the input encoded bit stream is inputted to the entropydecoding unit 301, the entropy decoding unit 301 decodes the inputencoded bit stream, and outputs the decoded values to the inversequantization unit 302. The inverse quantization unit 302 inverselyquantizes the decoded values, and outputs the frequency coefficients tothe inverse transformation unit 303. The inverse transformation unit 303performs inverse frequency transform on the frequency coefficients totransform the frequency coefficients into sample values, and outputs theresulting pixel values to an adder. The adder adds the resulting pixelvalues to the predicted video/image values outputted from theintra/inter prediction unit 306, 307, and outputs the resulting valuesto display, and outputs the resulting values to the block memory 304 orthe frame memory 305 (through the frame memory control unit 308) forfurther prediction. In addition, the intra/inter prediction unit 306,307 searches within videos/images stored in the block memory 304 orframe memory 305, and estimates a video/image area which is e.g. mostsimilar to the decoded videos/images for prediction.

The frame memory control unit 308 manages the reconstructed picturesstored in the frame memory 305. It reads frame memory control parametersfrom the entropy decoding unit 301 and performs memory controloperations accordingly.

(Decoding Process)

FIG. 14 is a flowchart which shows a picture decoding process 700according to the third embodiment of the present invention.

Step 901 parses a plurality of buffer descriptions (e.g. 1300 of FIG.12A) from a sequence parameter set of a coded video bitstream. A bufferdescription is an absolute description of the reference pictures (storedin a buffer) used in the decoding process of the current and futurecoded pictures. An another possible name for buffer description isreference picture set (RPS). Next, Step 902 parses a plurality ofupdating parameters (e.g. 1302, 1304 and 1308 of FIG. 12B and FIG. 12C)from a slice header of said coded video bitstream for selecting andmodifying one buffer description out of said plurality of bufferdescriptions. Step 903 decodes a slice from said coded video bitstreamusing said slice header and said modified buffer description.

Said updating parameters parsed from a slice header in Step 902 comprisea buffer description identifier (e.g. 1304 of FIG. 12C) for selecting abuffer description, a buffer element identifier for selecting a bufferelement within said selected buffer description, and a pictureidentifier (e.g. 1308 of FIG. 12C) for reassigning a unique referencepicture to be associated with said selected buffer element within saidselected buffer description. A buffer description consists of aplurality of buffer elements, where each buffer element corresponds to aunique reference picture stored in the picture memory.

Said updating parameters written into a slice header in Step 902 mayadditionally comprise a flag/parameter (e.g. 1302 of FIG. 12B) toindicate whether or not a selected buffer description is modified. Whenthe flag indicates that a selected buffer description is not modified,said selected buffer description is used according to its initialdefinition in sequence parameter set. According to the third embodimentof the present invention, said updating parameters in said slice header(Step 902) selects and modifies only one buffer description out of saidplurality of buffer descriptions defined in the sequence parameter set.

The buffer description modifications specified in different sliceheaders are independent of each other. That is, the modificationsspecified in a slice header only apply to the encoding/decoding of theassociated slice and do not apply to any other slices; furthermore, themodifications specified in each slice header active are applied on topof the initial buffer descriptions defined in the sequence parameterset.

In a possible implementation of the present invention, said sequenceparameter set parsed in Step 901 comprises a flag (e.g. 1312 of FIG.12A) to indicate whether or not said plurality of buffer description ispresent in said sequence parameter set. When buffer descriptions are notpresent in said sequence parameter set, said updating parameters in aslice header comprise a plurality of parameters for creating a bufferdescription (e.g. 1310 of FIG. 12C).

(Effects of Decoding Invention)

The effect of the present invention is to enable the decoding of a codedvideo bitstream which is coded in the form of improved coding efficiencyand harmonized design of buffer description data.

As above, a method of encoding video according to an aspect of thepresent invention including: writing a plurality of predetermined bufferdescriptions into a sequence parameter set of a coded video bitstream;writing a plurality of updating parameters into a picture parameter setof said coded video bitstream for modifying a subset of bufferdescriptions out of said plurality of buffer descriptions; writing abuffer description identifier into a header of a picture in said codedvideo bitstream for selecting one buffer description out of saidplurality of modified buffer descriptions; encoding said picture intosaid coded video bitstream using said picture parameter set and saidselected buffer description.

Furthermore, a method of decoding video including: parsing a pluralityof buffer descriptions from a sequence parameter set of a coded videobitstream; parsing a plurality of updating parameters from a pictureparameter set of said coded video bitstream for modifying a subset ofbuffer descriptions out of said plurality of buffer descriptions;parsing a buffer description identifier from a header of a picture insaid coded video bitstream for selecting one buffer description out ofsaid plurality of modified buffer descriptions; decoding said picturefrom said coded video bitstream using said picture parameter set andsaid selected buffer description.

Furthermore, a method of encoding video including: writing a pluralityof predetermined buffer descriptions into a sequence parameter set of acoded video bitstream; writing a plurality of updating parameters into apicture parameter set of said coded video bitstream for selecting andmodifying one buffer description out of said plurality of bufferdescriptions; encoding one or a plurality of pictures into said codedvideo bitstream using said picture parameter set and said modifiedbuffer description.

Furthermore, a method of decoding video including: parsing a pluralityof buffer descriptions from a sequence parameter set of a coded videobitstream; writing a plurality of updating parameters into a pictureparameter set of said coded video bitstream for selecting and modifyingone buffer description out of said plurality of buffer descriptions;decoding one or a plurality of pictures from said coded video bitstreamusing said picture parameter set and said modified buffer description.

Furthermore, a method of encoding video including: writing a pluralityof predetermined buffer descriptions into a sequence parameter set of acoded video bitstream; writing a plurality of updating parameters into aslice header of said coded video bitstream for selecting and modifyingone buffer description out of said plurality of buffer descriptions;encoding a slice into said coded video bitstream using said slice headerand said modified buffer description.

Furthermore, a method of decoding video including: parsing a pluralityof buffer descriptions from a sequence parameter set of a coded videobitstream; parsing a plurality of updating parameters from a sliceheader of said coded video bitstream for selecting and modifying onebuffer description out of said plurality of buffer descriptions;decoding a slice from said coded video bitstream using said slice headerand said modified buffer description.

Furthermore, the method of encoding or decoding video, whereas saidupdating parameters include: a buffer description identifier forselecting a buffer description; a buffer element identified forselecting a buffer element within said selected buffer description,whereas a buffer element corresponds to a unique reference picture; apicture identifier for reassigning a unique reference picture to beassociated with said selected buffer element within said selected bufferdescription.

Furthermore, the method of encoding or decoding video, whereas saidupdating parameters indicate that none of said buffer descriptionswritten in said sequence parameter set is modified.

Furthermore, the method of encoding or decoding video, whereas saidupdating parameters include the parameters for creating an additionalplurality of buffer descriptions in addition to said plurality of bufferdescriptions written in said sequence parameter set.

Furthermore, the method for encoding or decoding video, whereas saidpicture parameter set includes a flag to indicate whether or not aselected buffer description is modified, wherein when said flagindicates that a selected buffer description is not modified, saidupdating parameters selects one buffer description out of said pluralityof buffer descriptions but does not modify said selected bufferdescription.

Furthermore, the method for encoding or decoding video, whereas saidslice header includes a flag to indicate whether or not a selectedbuffer description is modified, wherein when said flag indicates that aselected buffer description is not modified, said updating parametersselects one buffer description out of said plurality of bufferdescriptions but does not modify said selected buffer description.

Furthermore, the method of encoding or decoding video, whereas saidsequence parameter set includes a flag to indicate whether or not bufferdescriptions are present in said sequence parameter set.

Furthermore, the method of encoding or decoding video, wherein whenbuffer descriptions are not present in said sequence parameter set asindicated by said flag, said updating parameters in said pictureparameter set include the parameters for creating one or more bufferdescriptions.

Furthermore, the method of encoding or decoding video, wherein whenbuffer descriptions are not present in said sequence parameter set asindicated by said flag, said updating parameters in said pictureparameter set include the parameters for creating a buffer description.

Furthermore, the method of encoding or decoding video, wherein whenbuffer descriptions are not present in said sequence parameter set asindicated by said flag, said updating parameters in said slice headerinclude the parameters for creating a buffer description.

Furthermore, a video bit stream encoding apparatus including: a writingunit operable to write a plurality of predetermined buffer descriptionsinto a sequence parameter set of a coded video bitstream; a writing unitoperable to write a plurality of updating parameters into a pictureparameter set of said coded video bitstream for modifying a subset ofbuffer descriptions out of said plurality of buffer descriptions; awriting unit operable to write a buffer description identifier into aheader of a picture in said coded video bitstream for selecting onebuffer description out of said plurality of modified bufferdescriptions; an encoding unit operable to encode said picture into saidcoded video bitstream using said picture parameter set and said selectedbuffer description.

Furthermore, a video bit stream decoding apparatus including: a parsingunit operable to parse a plurality of buffer descriptions from asequence parameter set of a coded video bitstream; a parsing unitoperable to parse a plurality of updating parameters from a pictureparameter set of said coded video bitstream for modifying a subset ofbuffer descriptions out of said plurality of buffer descriptions; aparsing unit operable to parse a buffer description identifier from aheader of a picture in said coded video bitstream for selecting onebuffer description out of said plurality of modified bufferdescriptions; a decoding unit operable to decode said picture from saidcoded video bitstream using said picture parameter set and said selectedbuffer description.

Furthermore, a video bit stream encoding apparatus including: a writingunit operable to write a plurality of predetermined buffer descriptionsinto a sequence parameter set of a coded video bitstream; a writing unitoperable to write a plurality of updating parameters into a pictureparameter set of said coded video bitstream for selecting and modifyingone buffer description out of said plurality of buffer descriptions; anencoding unit operable to encode one or a plurality of pictures intosaid coded video bitstream using said picture parameter set and saidmodified buffer description.

Furthermore, a video bit stream decoding apparatus including: a parsingunit operable to parse a plurality of buffer descriptions from asequence parameter set of a coded video bitstream; a writing unitoperable to write a plurality of updating parameters into a pictureparameter set of said coded video bitstream for selecting and modifyingone buffer description out of said plurality of buffer descriptions; adecoding unit operable to decode one or a plurality of pictures fromsaid coded video bitstream using said picture parameter set and saidmodified buffer description.

Furthermore, a video bit stream encoding apparatus including: a writingunit operable to write a plurality of predetermined buffer descriptionsinto a sequence parameter set of a coded video bitstream; a writing unitoperable to write a plurality of updating parameters into a slice headerof said coded video bitstream for selecting and modifying one bufferdescription out of said plurality of buffer descriptions; an encodingunit operable to encode a slice into said coded video bitstream usingsaid slice header and said modified buffer description.

Furthermore, a video bit stream decoding apparatus including: a parsingunit operable to parse a plurality of buffer descriptions from asequence parameter set of a coded video bitstream; a parsing unitoperable to parse a plurality of updating parameters from a slice headerof said coded video bitstream for selecting and modifying one bufferdescription out of said plurality of buffer descriptions; a decodingunit operable to decode a slice from said coded video bitstream usingsaid slice header and said modified buffer description.

Furthermore, the video bit stream encoding or decoding apparatuses,whereas said updating parameters include: a buffer descriptionidentifier for selecting a buffer description; a buffer elementidentified for selecting a buffer element within said selected bufferdescription, whereas a buffer element corresponds to a unique referencepicture; a picture identifier for reassigning a unique reference pictureto be associated with said selected buffer element within said selectedbuffer description.

Furthermore, the video bit stream encoding or decoding apparatuses,whereas said updating parameters indicate that none of said bufferdescriptions written in said sequence parameter set is modified.

Furthermore, the video bit stream encoding or decoding apparatuses,whereas said updating parameters include the parameters for creating anadditional plurality of buffer descriptions in addition to saidplurality of buffer descriptions written in said sequence parameter set.

Furthermore, the video bit stream encoding or decoding apparatuses,whereas said picture parameter set includes a flag to indicate whetheror not a selected buffer description is modified, wherein when said flagindicates that a selected buffer description is not modified, saidupdating parameters selects one buffer description out of said pluralityof buffer descriptions but does not modify said selected bufferdescription.

Furthermore, the video bit stream encoding or decoding apparatuses,whereas said slice header includes a flag to indicate whether or not aselected buffer description is modified, wherein when said flagindicates that a selected buffer description is not modified, saidupdating parameters selects one buffer description out of said pluralityof buffer descriptions but does not modify said selected bufferdescription.

Furthermore, the video bit stream encoding or decoding apparatuses,whereas said sequence parameter set includes a flag to indicate whetheror not buffer descriptions are present in said sequence parameter set.

Furthermore, the video bit stream encoding or decoding apparatuses,wherein when buffer descriptions are not present in said sequenceparameter set as indicated by said flag, said updating parameters insaid picture parameter set include the parameters for creating one ormore buffer descriptions.

Furthermore, the video bit stream encoding or decoding apparatuses,wherein when buffer descriptions are not present in said sequenceparameter set as indicated by said flag, said updating parameters insaid picture parameter set include the parameters for creating a bufferdescription.

Furthermore, the video bit stream encoding or decoding apparatuses,wherein when buffer descriptions are not present in said sequenceparameter set as indicated by said flag, said updating parameters insaid slice header include the parameters for creating a bufferdescription.

It should be noted that these general and specific aspects may beimplemented using a system, a method, an integrated circuit, a computerprogram, or a recording medium, or any combination of systems, methods,integrated circuits, computer programs, or recording media.

Embodiment 4

The processing described in each of embodiments can be simplyimplemented in an independent computer system, by recording, in arecording medium, a program for implementing the configurations of themoving picture coding method (image coding method) and the movingpicture decoding method (image decoding method) described in each ofembodiments. The recording media may be any recording media as long asthe program can be recorded, such as a magnetic disk, an optical disk, amagnetic optical disk, an IC card, and a semiconductor memory.

Hereinafter, the applications to the moving picture coding method (imagecoding method) and the moving picture decoding method (image decodingmethod) described in each of embodiments and systems using thereof willbe described. The system has a feature of having an image coding anddecoding apparatus that includes an image coding apparatus using theimage coding method and an image decoding apparatus using the imagedecoding method. Other configurations in the system can be changed asappropriate depending on the cases.

FIG. 15 illustrates an overall configuration of a content providingsystem ex100 for implementing content distribution services. The areafor providing communication services is divided into cells of desiredsize, and base stations ex106, ex107, ex108, ex109, and ex110 which arefixed wireless stations are placed in each of the cells.

The content providing system ex100 is connected to devices, such as acomputer ex111, a personal digital assistant (PDA) ex112, a cameraex113, a cellular phone ex114 and a game machine ex115, via the Internetex101, an Internet service provider ex102, a telephone network ex104, aswell as the base stations ex106 to ex110, respectively.

However, the configuration of the content providing system ex100 is notlimited to the configuration shown in FIG. 15, and a combination inwhich any of the elements are connected is acceptable. In addition, eachdevice may be directly connected to the telephone network ex104, ratherthan via the base stations ex106 to ex110 which are the fixed wirelessstations. Furthermore, the devices may be interconnected to each othervia a short distance wireless communication and others.

The camera ex113, such as a digital video camera, is capable ofcapturing video. A camera ex116, such as a digital camera, is capable ofcapturing both still images and video. Furthermore, the cellular phoneex114 may be the one that meets any of the standards such as GlobalSystem for Mobile Communications (GSM) (registered trademark), CodeDivision Multiple Access (CDMA), Wideband-Code Division Multiple Access(W-CDMA), Long Term Evolution (LTE), and High Speed Packet Access(HSPA). Alternatively, the cellular phone ex114 may be a PersonalHandyphone System (PHS).

In the content providing system ex100, a streaming server ex103 isconnected to the camera ex113 and others via the telephone network ex104and the base station ex109, which enables distribution of images of alive show and others. In such a distribution, a content (for example,video of a music live show) captured by the user using the camera ex113is coded as described above in each of embodiments (i.e., the camerafunctions as the image coding apparatus according to an aspect of thepresent invention), and the coded content is transmitted to thestreaming server ex103. On the other hand, the streaming server ex103carries out stream distribution of the transmitted content data to theclients upon their requests. The clients include the computer ex111, thePDA ex112, the camera ex113, the cellular phone ex114, and the gamemachine ex115 that are capable of decoding the above-mentioned codeddata. Each of the devices that have received the distributed datadecodes and reproduces the coded data (i.e., functions as the imagedecoding apparatus according to an aspect of the present invention).

The captured data may be coded by the camera ex113 or the streamingserver ex103 that transmits the data, or the coding processes may beshared between the camera ex113 and the streaming server ex103.Similarly, the distributed data may be decoded by the clients or thestreaming server ex103, or the decoding processes may be shared betweenthe clients and the streaming server ex103. Furthermore, the data of thestill images and video captured by not only the camera ex113 but alsothe camera ex116 may be transmitted to the streaming server ex103through the computer ex111. The coding processes may be performed by thecamera ex116, the computer ex111, or the streaming server ex103, orshared among them.

Furthermore, the coding and decoding processes may be performed by anLSI ex500 generally included in each of the computer ex111 and thedevices. The LSI ex500 may be configured of a single chip or a pluralityof chips. Software for coding and decoding video may be integrated intosome type of a recording medium (such as a CD-ROM, a flexible disk, anda hard disk) that is readable by the computer ex111 and others, and thecoding and decoding processes may be performed using the software.Furthermore, when the cellular phone ex114 is equipped with a camera,the video data obtained by the camera may be transmitted. The video datais data coded by the LSI ex500 included in the cellular phone ex114.

Furthermore, the streaming server ex103 may be composed of servers andcomputers, and may decentralize data and process the decentralized data,record, or distribute data.

As described above, the clients may receive and reproduce the coded datain the content providing system ex100. In other words, the clients canreceive and decode information transmitted by the user, and reproducethe decoded data in real time in the content providing system ex100, sothat the user who does not have any particular right and equipment canimplement personal broadcasting.

Aside from the example of the content providing system ex100, at leastone of the moving picture coding apparatus (image coding apparatus) andthe moving picture decoding apparatus (image decoding apparatus)described in each of embodiments may be implemented in a digitalbroadcasting system ex200 illustrated in FIG. 16. More specifically, abroadcast station ex201 communicates or transmits, via radio waves to abroadcast satellite ex202, multiplexed data obtained by multiplexingaudio data and others onto video data. The video data is data coded bythe moving picture coding method described in each of embodiments (i.e.,data coded by the image coding apparatus according to an aspect of thepresent invention). Upon receipt of the multiplexed data, the broadcastsatellite ex202 transmits radio waves for broadcasting. Then, a home-useantenna ex204 with a satellite broadcast reception function receives theradio waves. Next, a device such as a television (receiver) ex300 and aset top box (STB) ex217 decodes the received multiplexed data, andreproduces the decoded data (i.e., functions as the image decodingapparatus according to an aspect of the present invention).

Furthermore, a reader/recorder ex218 (i) reads and decodes themultiplexed data recorded on a recording medium ex215, such as a DVD anda BD, or (i) codes video signals in the recording medium ex215, and insome cases, writes data obtained by multiplexing an audio signal on thecoded data. The reader/recorder ex218 can include the moving picturedecoding apparatus or the moving picture coding apparatus as shown ineach of embodiments. In this case, the reproduced video signals aredisplayed on the monitor ex219, and can be reproduced by another deviceor system using the recording medium ex215 on which the multiplexed datais recorded. It is also possible to implement the moving picturedecoding apparatus in the set top box ex217 connected to the cable ex203for a cable television or to the antenna ex204 for satellite and/orterrestrial broadcasting, so as to display the video signals on themonitor ex219 of the television ex300. The moving picture decodingapparatus may be implemented not in the set top box but in thetelevision ex300.

FIG. 17 illustrates the television (receiver) ex300 that uses the movingpicture coding method and the moving picture decoding method describedin each of embodiments. The television ex300 includes: a tuner ex301that obtains or provides multiplexed data obtained by multiplexing audiodata onto video data, through the antenna ex204 or the cable ex203, etc.that receives a broadcast; a modulation/demodulation unit ex302 thatdemodulates the received multiplexed data or modulates data intomultiplexed data to be supplied outside; and amultiplexing/demultiplexing unit ex303 that demultiplexes the modulatedmultiplexed data into video data and audio data, or multiplexes videodata and audio data coded by a signal processing unit ex306 into data.

The television ex300 further includes: a signal processing unit ex306including an audio signal processing unit ex304 and a video signalprocessing unit ex305 that decode audio data and video data and codeaudio data and video data, respectively (which function as the imagecoding apparatus and the image decoding apparatus according to theaspects of the present invention); and an output unit ex309 including aspeaker ex307 that provides the decoded audio signal, and a display unitex308 that displays the decoded video signal, such as a display.Furthermore, the television ex300 includes an interface unit ex317including an operation input unit ex312 that receives an input of a useroperation. Furthermore, the television ex300 includes a control unitex310 that controls overall each constituent element of the televisionex300, and a power supply circuit unit ex311 that supplies power to eachof the elements. Other than the operation input unit ex312, theinterface unit ex317 may include: a bridge ex313 that is connected to anexternal device, such as the reader/recorder ex218; a slot unit ex314for enabling attachment of the recording medium ex216, such as an SDcard; a driver ex315 to be connected to an external recording medium,such as a hard disk; and a modem ex316 to be connected to a telephonenetwork. Here, the recording medium ex216 can electrically recordinformation using a non-volatile/volatile semiconductor memory elementfor storage. The constituent elements of the television ex300 areconnected to each other through a synchronous bus.

First, the configuration in which the television ex300 decodesmultiplexed data obtained from outside through the antenna ex204 andothers and reproduces the decoded data will be described. In thetelevision ex300, upon a user operation through a remote controllerex220 and others, the multiplexing/demultiplexing unit ex303demultiplexes the multiplexed data demodulated by themodulation/demodulation unit ex302, under control of the control unitex310 including a CPU. Furthermore, the audio signal processing unitex304 decodes the demultiplexed audio data, and the video signalprocessing unit ex305 decodes the demultiplexed video data, using thedecoding method described in each of embodiments, in the televisionex300. The output unit ex309 provides the decoded video signal and audiosignal outside, respectively. When the output unit ex309 provides thevideo signal and the audio signal, the signals may be temporarily storedin buffers ex318 and ex319, and others so that the signals arereproduced in synchronization with each other. Furthermore, thetelevision ex300 may read multiplexed data not through a broadcast andothers but from the recording media ex215 and ex216, such as a magneticdisk, an optical disk, and a SD card. Next, a configuration in which thetelevision ex300 codes an audio signal and a video signal, and transmitsthe data outside or writes the data on a recording medium will bedescribed. In the television ex300, upon a user operation through theremote controller ex220 and others, the audio signal processing unitex304 codes an audio signal, and the video signal processing unit ex305codes a video signal, under control of the control unit ex310 using thecoding method described in each of embodiments. Themultiplexing/demultiplexing unit ex303 multiplexes the coded videosignal and audio signal, and provides the resulting signal outside. Whenthe multiplexing/demultiplexing unit ex303 multiplexes the video signaland the audio signal, the signals may be temporarily stored in thebuffers ex320 and ex321, and others so that the signals are reproducedin synchronization with each other. Here, the buffers ex318, ex319,ex320, and ex321 may be plural as illustrated, or at least one buffermay be shared in the television ex300. Furthermore, data may be storedin a buffer so that the system overflow and underflow may be avoidedbetween the modulation/demodulation unit ex302 and themultiplexing/demultiplexing unit ex303, for example.

Furthermore, the television ex300 may include a configuration forreceiving an AV input from a microphone or a camera other than theconfiguration for obtaining audio and video data from a broadcast or arecording medium, and may code the obtained data. Although thetelevision ex300 can code, multiplex, and provide outside data in thedescription, it may be capable of only receiving, decoding, andproviding outside data but not the coding, multiplexing, and providingoutside data.

Furthermore, when the reader/recorder ex218 reads or writes multiplexeddata from or on a recording medium, one of the television ex300 and thereader/recorder ex218 may decode or code the multiplexed data, and thetelevision ex300 and the reader/recorder ex218 may share the decoding orcoding.

As an example, FIG. 18 illustrates a configuration of an informationreproducing/recording unit ex400 when data is read or written from or onan optical disk. The information reproducing/recording unit ex400includes constituent elements ex401, ex402, ex403, ex404, ex405, ex406,and ex407 to be described hereinafter. The optical head ex401 irradiatesa laser spot in a recording surface of the recording medium ex215 thatis an optical disk to write information, and detects reflected lightfrom the recording surface of the recording medium ex215 to read theinformation. The modulation recording unit ex402 electrically drives asemiconductor laser included in the optical head ex401, and modulatesthe laser light according to recorded data. The reproductiondemodulating unit ex403 amplifies a reproduction signal obtained byelectrically detecting the reflected light from the recording surfaceusing a photo detector included in the optical head ex401, anddemodulates the reproduction signal by separating a signal componentrecorded on the recording medium ex215 to reproduce the necessaryinformation. The buffer ex404 temporarily holds the information to berecorded on the recording medium ex215 and the information reproducedfrom the recording medium ex215. The disk motor ex405 rotates therecording medium ex215. The servo control unit ex406 moves the opticalhead ex401 to a predetermined information track while controlling therotation drive of the disk motor ex405 so as to follow the laser spot.The system control unit ex407 controls overall the informationreproducing/recording unit ex400. The reading and writing processes canbe implemented by the system control unit ex407 using variousinformation stored in the buffer ex404 and generating and adding newinformation as necessary, and by the modulation recording unit ex402,the reproduction demodulating unit ex403, and the servo control unitex406 that record and reproduce information through the optical headex401 while being operated in a coordinated manner. The system controlunit ex407 includes, for example, a microprocessor, and executesprocessing by causing a computer to execute a program for read andwrite.

Although the optical head ex401 irradiates a laser spot in thedescription, it may perform high-density recording using near fieldlight.

FIG. 19 illustrates the recording medium ex215 that is the optical disk.On the recording surface of the recording medium ex215, guide groovesare spirally formed, and an information track ex230 records, in advance,address information indicating an absolute position on the diskaccording to change in a shape of the guide grooves. The addressinformation includes information for determining positions of recordingblocks ex231 that are a unit for recording data. Reproducing theinformation track ex230 and reading the address information in anapparatus that records and reproduces data can lead to determination ofthe positions of the recording blocks. Furthermore, the recording mediumex215 includes a data recording area ex233, an inner circumference areaex232, and an outer circumference area ex234. The data recording areaex233 is an area for use in recording the user data. The innercircumference area ex232 and the outer circumference area ex234 that areinside and outside of the data recording area ex233, respectively arefor specific use except for recording the user data. The informationreproducing/recording unit 400 reads and writes coded audio, coded videodata, or multiplexed data obtained by multiplexing the coded audio andvideo data, from and on the data recording area ex233 of the recordingmedium ex215.

Although an optical disk having a layer, such as a DVD and a BD isdescribed as an example in the description, the optical disk is notlimited to such, and may be an optical disk having a multilayerstructure and capable of being recorded on a part other than thesurface. Furthermore, the optical disk may have a structure formultidimensional recording/reproduction, such as recording ofinformation using light of colors with different wavelengths in the sameportion of the optical disk and for recording information havingdifferent layers from various angles.

Furthermore, a car ex210 having an antenna ex205 can receive data fromthe satellite ex202 and others, and reproduce video on a display devicesuch as a car navigation system ex211 set in the car ex210, in thedigital broadcasting system ex200. Here, a configuration of the carnavigation system ex211 will be a configuration, for example, includinga GPS receiving unit from the configuration illustrated in FIG. 17. Thesame will be true for the configuration of the computer ex111, thecellular phone ex114, and others.

FIG. 20A illustrates the cellular phone ex114 that uses the movingpicture coding method and the moving picture decoding method describedin embodiments. The cellular phone ex114 includes: an antenna ex350 fortransmitting and receiving radio waves through the base station ex110; acamera unit ex365 capable of capturing moving and still images; and adisplay unit ex358 such as a liquid crystal display for displaying thedata such as decoded video captured by the camera unit ex365 or receivedby the antenna ex350. The cellular phone ex114 further includes: a mainbody unit including an operation key unit ex366; an audio output unitex357 such as a speaker for output of audio; an audio input unit ex356such as a microphone for input of audio; a memory unit ex367 for storingcaptured video or still pictures, recorded audio, coded or decoded dataof the received video, the still pictures, e-mails, or others; and aslot unit ex364 that is an interface unit for a recording medium thatstores data in the same manner as the memory unit ex367.

Next, an example of a configuration of the cellular phone ex114 will bedescribed with reference to FIG. 20B. In the cellular phone ex114, amain control unit ex360 designed to control overall each unit of themain body including the display unit ex358 as well as the operation keyunit ex366 is connected mutually, via a synchronous bus ex370, to apower supply circuit unit ex361, an operation input control unit ex362,a video signal processing unit ex355, a camera interface unit ex363, aliquid crystal display (LCD) control unit ex359, amodulation/demodulation unit ex352, a multiplexing/demultiplexing unitex353, an audio signal processing unit ex354, the slot unit ex364, andthe memory unit ex367.

When a call-end key or a power key is turned ON by a user's operation,the power supply circuit unit ex361 supplies the respective units withpower from a battery pack so as to activate the cell phone ex114.

In the cellular phone ex114, the audio signal processing unit ex354converts the audio signals collected by the audio input unit ex356 invoice conversation mode into digital audio signals under the control ofthe main control unit ex360 including a CPU, ROM, and RAM. Then, themodulation/demodulation unit ex352 performs spread spectrum processingon the digital audio signals, and the transmitting and receiving unitex351 performs digital-to-analog conversion and frequency conversion onthe data, so as to transmit the resulting data via the antenna ex350.Also, in the cellular phone ex114, the transmitting and receiving unitex351 amplifies the data received by the antenna ex350 in voiceconversation mode and performs frequency conversion and theanalog-to-digital conversion on the data. Then, themodulation/demodulation unit ex352 performs inverse spread spectrumprocessing on the data, and the audio signal processing unit ex354converts it into analog audio signals, so as to output them via theaudio output unit ex357.

Furthermore, when an e-mail in data communication mode is transmitted,text data of the e-mail inputted by operating the operation key unitex366 and others of the main body is sent out to the main control unitex360 via the operation input control unit ex362. The main control unitex360 causes the modulation/demodulation unit ex352 to perform spreadspectrum processing on the text data, and the transmitting and receivingunit ex351 performs the digital-to-analog conversion and the frequencyconversion on the resulting data to transmit the data to the basestation ex110 via the antenna ex350. When an e-mail is received,processing that is approximately inverse to the processing fortransmitting an e-mail is performed on the received data, and theresulting data is provided to the display unit ex358.

When video, still images, or video and audio in data communication modeis or are transmitted, the video signal processing unit ex355 compressesand codes video signals supplied from the camera unit ex365 using themoving picture coding method shown in each of embodiments (i.e.,functions as the image coding apparatus according to the aspect of thepresent invention), and transmits the coded video data to themultiplexing/demultiplexing unit ex353. In contrast, during when thecamera unit ex365 captures video, still images, and others, the audiosignal processing unit ex354 codes audio signals collected by the audioinput unit ex356, and transmits the coded audio data to themultiplexing/demultiplexing unit ex353.

The multiplexing/demultiplexing unit ex353 multiplexes the coded videodata supplied from the video signal processing unit ex355 and the codedaudio data supplied from the audio signal processing unit ex354, using apredetermined method. Then, the modulation/demodulation unit(modulation/demodulation circuit unit) ex352 performs spread spectrumprocessing on the multiplexed data, and the transmitting and receivingunit ex351 performs digital-to-analog conversion and frequencyconversion on the data so as to transmit the resulting data via theantenna ex350.

When receiving data of a video file which is linked to a Web page andothers in data communication mode or when receiving an e-mail with videoand/or audio attached, in order to decode the multiplexed data receivedvia the antenna ex350, the multiplexing/demultiplexing unit ex353demultiplexes the multiplexed data into a video data bit stream and anaudio data bit stream, and supplies the video signal processing unitex355 with the coded video data and the audio signal processing unitex354 with the coded audio data, through the synchronous bus ex370. Thevideo signal processing unit ex355 decodes the video signal using amoving picture decoding method corresponding to the moving picturecoding method shown in each of embodiments (i.e., functions as the imagedecoding apparatus according to the aspect of the present invention),and then the display unit ex358 displays, for instance, the video andstill images included in the video file linked to the Web page via theLCD control unit ex359. Furthermore, the audio signal processing unitex354 decodes the audio signal, and the audio output unit ex357 providesthe audio.

Furthermore, similarly to the television ex300, a terminal such as thecellular phone ex114 probably have 3 types of implementationconfigurations including not only (i) a transmitting and receivingterminal including both a coding apparatus and a decoding apparatus, butalso (ii) a transmitting terminal including only a coding apparatus and(iii) a receiving terminal including only a decoding apparatus. Althoughthe digital broadcasting system ex200 receives and transmits themultiplexed data obtained by multiplexing audio data onto video data inthe description, the multiplexed data may be data obtained bymultiplexing not audio data but character data related to video ontovideo data, and may be not multiplexed data but video data itself.

As such, the moving picture coding method and the moving picturedecoding method in each of embodiments can be used in any of the devicesand systems described. Thus, the advantages described in each ofembodiments can be obtained.

Furthermore, the present invention is not limited to embodiments, andvarious modifications and revisions are possible without departing fromthe scope of the present invention.

Embodiment 5

Video data can be generated by switching, as necessary, between (i) themoving picture coding method or the moving picture coding apparatusshown in each of embodiments and (ii) a moving picture coding method ora moving picture coding apparatus in conformity with a differentstandard, such as MPEG-2, MPEG-4 AVC, and VC-1.

Here, when a plurality of video data that conforms to the differentstandards is generated and is then decoded, the decoding methods need tobe selected to conform to the different standards. However, since towhich standard each of the plurality of the video data to be decodedconform cannot be detected, there is a problem that an appropriatedecoding method cannot be selected.

In order to solve the problem, multiplexed data obtained by multiplexingaudio data and others onto video data has a structure includingidentification information indicating to which standard the video dataconforms. The specific structure of the multiplexed data including thevideo data generated in the moving picture coding method and by themoving picture coding apparatus shown in each of embodiments will behereinafter described. The multiplexed data is a digital stream in theMPEG-2 Transport Stream format.

FIG. 21 illustrates a structure of the multiplexed data. As illustratedin FIG. 21, the multiplexed data can be obtained by multiplexing atleast one of a video stream, an audio stream, a presentation graphicsstream (PG), and an interactive graphics stream. The video streamrepresents primary video and secondary video of a movie, the audiostream (IG) represents a primary audio part and a secondary audio partto be mixed with the primary audio part, and the presentation graphicsstream represents subtitles of the movie. Here, the primary video isnormal video to be displayed on a screen, and the secondary video isvideo to be displayed on a smaller window in the primary video.Furthermore, the interactive graphics stream represents an interactivescreen to be generated by arranging the GUI components on a screen. Thevideo stream is coded in the moving picture coding method or by themoving picture coding apparatus shown in each of embodiments, or in amoving picture coding method or by a moving picture coding apparatus inconformity with a conventional standard, such as MPEG-2, MPEG-4 AVC, andVC-1. The audio stream is coded in accordance with a standard, such asDolby-AC-3, Dolby Digital Plus, MLP, DTS, DTS-HD, and linear PCM.

Each stream included in the multiplexed data is identified by PID. Forexample, 0x1011 is allocated to the video stream to be used for video ofa movie, 0x1100 to 0x111F are allocated to the audio streams, 0x1200 to0x121F are allocated to the presentation graphics streams, 0x1400 to0x141F are allocated to the interactive graphics streams, 0x1B00 to0x1B1F are allocated to the video streams to be used for secondary videoof the movie, and 0x1A00 to 0x1A1F are allocated to the audio streams tobe used for the secondary audio to be mixed with the primary audio.

FIG. 22 schematically illustrates how data is multiplexed. First, avideo stream ex235 composed of video frames and an audio stream ex238composed of audio frames are transformed into a stream of PES packetsex236 and a stream of PES packets ex239, and further into TS packetsex237 and TS packets ex240, respectively. Similarly, data of apresentation graphics stream ex241 and data of an interactive graphicsstream ex244 are transformed into a stream of PES packets ex242 and astream of PES packets ex245, and further into TS packets ex243 and TSpackets ex246, respectively. These TS packets are multiplexed into astream to obtain multiplexed data ex247.

FIG. 23 illustrates how a video stream is stored in a stream of PESpackets in more detail. The first bar in FIG. 23 shows a video framestream in a video stream. The second bar shows the stream of PESpackets. As indicated by arrows denoted as yy1, yy2, yy3, and yy4 inFIG. 23, the video stream is divided into pictures as I pictures, Bpictures, and P pictures each of which is a video presentation unit, andthe pictures are stored in a payload of each of the PES packets. Each ofthe PES packets has a PES header, and the PES header stores aPresentation Time-Stamp (PTS) indicating a display time of the picture,and a Decoding Time-Stamp (DTS) indicating a decoding time of thepicture.

FIG. 24 illustrates a format of TS packets to be finally written on themultiplexed data. Each of the TS packets is a 188-byte fixed lengthpacket including a 4-byte TS header having information, such as a PIDfor identifying a stream and a 184-byte TS payload for storing data. ThePES packets are divided, and stored in the TS payloads, respectively.When a BD ROM is used, each of the TS packets is given a 4-byteTP_Extra_Header, thus resulting in 192-byte source packets. The sourcepackets are written on the multiplexed data. The TP_Extra_Header storesinformation such as an Arrival_Time_Stamp (ATS). The ATS shows atransfer start time at which each of the TS packets is to be transferredto a PID filter. The source packets are arranged in the multiplexed dataas shown at the bottom of FIG. 24. The numbers incrementing from thehead of the multiplexed data are called source packet numbers (SPNs).

Each of the TS packets included in the multiplexed data includes notonly streams of audio, video, subtitles and others, but also a ProgramAssociation Table (PAT), a Program Map Table (PMT), and a Program ClockReference (PCR). The PAT shows what a PID in a PMT used in themultiplexed data indicates, and a PID of the PAT itself is registered aszero. The PMT stores PIDs of the streams of video, audio, subtitles andothers included in the multiplexed data, and attribute information ofthe streams corresponding to the PIDs. The PMT also has variousdescriptors relating to the multiplexed data. The descriptors haveinformation such as copy control information showing whether copying ofthe multiplexed data is permitted or not. The PCR stores STC timeinformation corresponding to an ATS showing when the PCR packet istransferred to a decoder, in order to achieve synchronization between anArrival Time Clock (ATC) that is a time axis of ATSs, and an System TimeClock (STC) that is a time axis of PTSs and DTSs.

FIG. 25 illustrates the data structure of the PMT in detail. A PMTheader is disposed at the top of the PMT. The PMT header describes thelength of data included in the PMT and others. A plurality ofdescriptors relating to the multiplexed data is disposed after the PMTheader. Information such as the copy control information is described inthe descriptors. After the descriptors, a plurality of pieces of streaminformation relating to the streams included in the multiplexed data isdisposed. Each piece of stream information includes stream descriptorseach describing information, such as a stream type for identifying acompression codec of a stream, a stream PID, and stream attributeinformation (such as a frame rate or an aspect ratio). The streamdescriptors are equal in number to the number of streams in themultiplexed data.

When the multiplexed data is recorded on a recording medium and others,it is recorded together with multiplexed data information files.

Each of the multiplexed data information files is management informationof the multiplexed data as shown in FIG. 26. The multiplexed datainformation files are in one to one correspondence with the multiplexeddata, and each of the files includes multiplexed data information,stream attribute information, and an entry map.

As illustrated in FIG. 26, the multiplexed data information includes asystem rate, a reproduction start time, and a reproduction end time. Thesystem rate indicates the maximum transfer rate at which a system targetdecoder to be described later transfers the multiplexed data to a PIDfilter. The intervals of the ATSs included in the multiplexed data areset to not higher than a system rate. The reproduction start timeindicates a PTS in a video frame at the head of the multiplexed data. Aninterval of one frame is added to a PTS in a video frame at the end ofthe multiplexed data, and the PTS is set to the reproduction end time.

As shown in FIG. 27, a piece of attribute information is registered inthe stream attribute information, for each PID of each stream includedin the multiplexed data. Each piece of attribute information hasdifferent information depending on whether the corresponding stream is avideo stream, an audio stream, a presentation graphics stream, or aninteractive graphics stream. Each piece of video stream attributeinformation carries information including what kind of compression codecis used for compressing the video stream, and the resolution, aspectratio and frame rate of the pieces of picture data that is included inthe video stream. Each piece of audio stream attribute informationcarries information including what kind of compression codec is used forcompressing the audio stream, how many channels are included in theaudio stream, which language the audio stream supports, and how high thesampling frequency is. The video stream attribute information and theaudio stream attribute information are used for initialization of adecoder before the player plays back the information.

In the present embodiment, the multiplexed data to be used is of astream type included in the PMT. Furthermore, when the multiplexed datais recorded on a recording medium, the video stream attributeinformation included in the multiplexed data information is used. Morespecifically, the moving picture coding method or the moving picturecoding apparatus described in each of embodiments includes a step or aunit for allocating unique information indicating video data generatedby the moving picture coding method or the moving picture codingapparatus in each of embodiments, to the stream type included in the PMTor the video stream attribute information. With the configuration, thevideo data generated by the moving picture coding method or the movingpicture coding apparatus described in each of embodiments can bedistinguished from video data that conforms to another standard.

Furthermore, FIG. 28 illustrates steps of the moving picture decodingmethod according to the present embodiment. In Step exS100, the streamtype included in the PMT or the video stream attribute informationincluded in the multiplexed data information is obtained from themultiplexed data. Next, in Step exS101, it is determined whether or notthe stream type or the video stream attribute information indicates thatthe multiplexed data is generated by the moving picture coding method orthe moving picture coding apparatus in each of embodiments. When it isdetermined that the stream type or the video stream attributeinformation indicates that the multiplexed data is generated by themoving picture coding method or the moving picture coding apparatus ineach of embodiments, in Step exS102, decoding is performed by the movingpicture decoding method in each of embodiments. Furthermore, when thestream type or the video stream attribute information indicatesconformance to the conventional standards, such as MPEG-2, MPEG-4 AVC,and VC-1, in Step exS103, decoding is performed by a moving picturedecoding method in conformity with the conventional standards.

As such, allocating a new unique value to the stream type or the videostream attribute information enables determination whether or not themoving picture decoding method or the moving picture decoding apparatusthat is described in each of embodiments can perform decoding. Even whenmultiplexed data that conforms to a different standard is input, anappropriate decoding method or apparatus can be selected. Thus, itbecomes possible to decode information without any error. Furthermore,the moving picture coding method or apparatus, or the moving picturedecoding method or apparatus in the present embodiment can be used inthe devices and systems described above.

Embodiment 6

Each of the moving picture coding method, the moving picture codingapparatus, the moving picture decoding method, and the moving picturedecoding apparatus in each of embodiments is typically achieved in theform of an integrated circuit or a Large Scale Integrated (LSI) circuit.As an example of the LSI, FIG. 29 illustrates a configuration of the LSIex500 that is made into one chip. The LSI ex500 includes elements ex501,ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509 to bedescribed below, and the elements are connected to each other through abus ex510. The power supply circuit unit ex505 is activated by supplyingeach of the elements with power when the power supply circuit unit ex505is turned on.

For example, when coding is performed, the LSI ex500 receives an AVsignal from a microphone ex117, a camera ex113, and others through an AVIO ex509 under control of a control unit ex501 including a CPU ex502, amemory controller ex503, a stream controller ex504, and a drivingfrequency control unit ex512. The received AV signal is temporarilystored in an external memory ex511, such as an SDRAM. Under control ofthe control unit ex501, the stored data is segmented into data portionsaccording to the processing amount and speed to be transmitted to asignal processing unit ex507. Then, the signal processing unit ex507codes an audio signal and/or a video signal. Here, the coding of thevideo signal is the coding described in each of embodiments.Furthermore, the signal processing unit ex507 sometimes multiplexes thecoded audio data and the coded video data, and a stream IO ex506provides the multiplexed data outside. The provided multiplexed data istransmitted to the base station ex107, or written on the recordingmedium ex215. When data sets are multiplexed, the data should betemporarily stored in the buffer ex508 so that the data sets aresynchronized with each other.

Although the memory ex511 is an element outside the LSI ex500, it may beincluded in the LSI ex500. The buffer ex508 is not limited to onebuffer, but may be composed of buffers. Furthermore, the LSI ex500 maybe made into one chip or a plurality of chips.

Furthermore, although the control unit ex501 includes the CPU ex502, thememory controller ex503, the stream controller ex504, the drivingfrequency control unit ex512, the configuration of the control unitex501 is not limited to such. For example, the signal processing unitex507 may further include a CPU. Inclusion of another CPU in the signalprocessing unit ex507 can improve the processing speed. Furthermore, asanother example, the CPU ex502 may serve as or be a part of the signalprocessing unit ex507, and, for example, may include an audio signalprocessing unit. In such a case, the control unit ex501 includes thesignal processing unit ex507 or the CPU ex502 including a part of thesignal processing unit ex507.

The name used here is LSI, but it may also be called IC, system LSI,super LSI, or ultra LSI depending on the degree of integration.

Moreover, ways to achieve integration are not limited to the LSI, and aspecial circuit or a general purpose processor and so forth can alsoachieve the integration. Field Programmable Gate Array (FPGA) that canbe programmed after manufacturing LSIs or a reconfigurable processorthat allows re-configuration of the connection or configuration of anLSI can be used for the same purpose.

In the future, with advancement in semiconductor technology, a brand-newtechnology may replace LSI. The functional blocks can be integratedusing such a technology. The possibility is that the present inventionis applied to biotechnology.

Embodiment 7

When video data generated in the moving picture coding method or by themoving picture coding apparatus described in each of embodiments isdecoded, compared to when video data that conforms to a conventionalstandard, such as MPEG-2, MPEG-4 AVC, and VC-1 is decoded, theprocessing amount probably increases. Thus, the LSI ex500 needs to beset to a driving frequency higher than that of the CPU ex502 to be usedwhen video data in conformity with the conventional standard is decoded.However, when the driving frequency is set higher, there is a problemthat the power consumption increases.

In order to solve the problem, the moving picture decoding apparatus,such as the television ex300 and the LSI ex500 is configured todetermine to which standard the video data conforms, and switch betweenthe driving frequencies according to the determined standard. FIG. 30illustrates a configuration ex800 in the present embodiment. A drivingfrequency switching unit ex803 sets a driving frequency to a higherdriving frequency when video data is generated by the moving picturecoding method or the moving picture coding apparatus described in eachof embodiments. Then, the driving frequency switching unit ex803instructs a decoding processing unit ex801 that executes the movingpicture decoding method described in each of embodiments to decode thevideo data. When the video data conforms to the conventional standard,the driving frequency switching unit ex803 sets a driving frequency to alower driving frequency than that of the video data generated by themoving picture coding method or the moving picture coding apparatusdescribed in each of embodiments. Then, the driving frequency switchingunit ex803 instructs the decoding processing unit ex802 that conforms tothe conventional standard to decode the video data.

More specifically, the driving frequency switching unit ex803 includesthe CPU ex502 and the driving frequency control unit ex512 in FIG. 29.Here, each of the decoding processing unit ex801 that executes themoving picture decoding method described in each of embodiments and thedecoding processing unit ex802 that conforms to the conventionalstandard corresponds to the signal processing unit ex507 in FIG. 29. TheCPU ex502 determines to which standard the video data conforms. Then,the driving frequency control unit ex512 determines a driving frequencybased on a signal from the CPU ex502. Furthermore, the signal processingunit ex507 decodes the video data based on the signal from the CPUex502. For example, the identification information described inEmbodiment 5 is probably used for identifying the video data. Theidentification information is not limited to the one described inEmbodiment 5 but may be any information as long as the informationindicates to which standard the video data conforms. For example, whenwhich standard video data conforms to can be determined based on anexternal signal for determining that the video data is used for atelevision or a disk, etc., the determination may be made based on suchan external signal. Furthermore, the CPU ex502 selects a drivingfrequency based on, for example, a look-up table in which the standardsof the video data are associated with the driving frequencies as shownin FIG. 32. The driving frequency can be selected by storing the look-uptable in the buffer ex508 and in an internal memory of an LSI, and withreference to the look-up table by the CPU ex502.

FIG. 31 illustrates steps for executing a method in the presentembodiment. First, in Step exS200, the signal processing unit ex507obtains identification information from the multiplexed data. Next, inStep exS201, the CPU ex502 determines whether or not the video data isgenerated by the coding method and the coding apparatus described ineach of embodiments, based on the identification information. When thevideo data is generated by the moving picture coding method and themoving picture coding apparatus described in each of embodiments, inStep exS202, the CPU ex502 transmits a signal for setting the drivingfrequency to a higher driving frequency to the driving frequency controlunit ex512. Then, the driving frequency control unit ex512 sets thedriving frequency to the higher driving frequency. On the other hand,when the identification information indicates that the video dataconforms to the conventional standard, such as MPEG-2, MPEG-4 AVC, andVC-1, in Step exS203, the CPU ex502 transmits a signal for setting thedriving frequency to a lower driving frequency to the driving frequencycontrol unit ex512. Then, the driving frequency control unit ex512 setsthe driving frequency to the lower driving frequency than that in thecase where the video data is generated by the moving picture codingmethod and the moving picture coding apparatus described in each ofembodiment.

Furthermore, along with the switching of the driving frequencies, thepower conservation effect can be improved by changing the voltage to beapplied to the LSI ex500 or an apparatus including the LSI ex500. Forexample, when the driving frequency is set lower, the voltage to beapplied to the LSI ex500 or the apparatus including the LSI ex500 isprobably set to a voltage lower than that in the case where the drivingfrequency is set higher.

Furthermore, when the processing amount for decoding is larger, thedriving frequency may be set higher, and when the processing amount fordecoding is smaller, the driving frequency may be set lower as themethod for setting the driving frequency. Thus, the setting method isnot limited to the ones described above. For example, when theprocessing amount for decoding video data in conformity with MPEG-4 AVCis larger than the processing amount for decoding video data generatedby the moving picture coding method and the moving picture codingapparatus described in each of embodiments, the driving frequency isprobably set in reverse order to the setting described above.

Furthermore, the method for setting the driving frequency is not limitedto the method for setting the driving frequency lower. For example, whenthe identification information indicates that the video data isgenerated by the moving picture coding method and the moving picturecoding apparatus described in each of embodiments, the voltage to beapplied to the LSI ex500 or the apparatus including the LSI ex500 isprobably set higher. When the identification information indicates thatthe video data conforms to the conventional standard, such as MPEG-2,MPEG-4 AVC, and VC-1, the voltage to be applied to the LSI ex500 or theapparatus including the LSI ex500 is probably set lower. As anotherexample, when the identification information indicates that the videodata is generated by the moving picture coding method and the movingpicture coding apparatus described in each of embodiments, the drivingof the CPU ex502 does not probably have to be suspended. When theidentification information indicates that the video data conforms to theconventional standard, such as MPEG-2, MPEG-4 AVC, and VC-1, the drivingof the CPU ex502 is probably suspended at a given time because the CPUex502 has extra processing capacity. Even when the identificationinformation indicates that the video data is generated by the movingpicture coding method and the moving picture coding apparatus describedin each of embodiments, in the case where the CPU ex502 has extraprocessing capacity, the driving of the CPU ex502 is probably suspendedat a given time. In such a case, the suspending time is probably setshorter than that in the case where when the identification informationindicates that the video data conforms to the conventional standard,such as MPEG-2, MPEG-4 AVC, and VC-1.

Accordingly, the power conservation effect can be improved by switchingbetween the driving frequencies in accordance with the standard to whichthe video data conforms. Furthermore, when the LSI ex500 or theapparatus including the LSI ex500 is driven using a battery, the batterylife can be extended with the power conservation effect.

Embodiment 8

There are cases where a plurality of video data that conforms todifferent standards, is provided to the devices and systems, such as atelevision and a cellular phone. In order to enable decoding theplurality of video data that conforms to the different standards, thesignal processing unit ex507 of the LSI ex500 needs to conform to thedifferent standards. However, the problems of increase in the scale ofthe circuit of the LSI ex500 and increase in the cost arise with theindividual use of the signal processing units ex507 that conform to therespective standards.

In order to solve the problem, what is conceived is a configuration inwhich the decoding processing unit for implementing the moving picturedecoding method described in each of embodiments and the decodingprocessing unit that conforms to the conventional standard, such asMPEG-2, MPEG-4 AVC, and VC-1 are partly shared. Ex900 in FIG. 33A showsan example of the configuration. For example, the moving picturedecoding method described in each of embodiments and the moving picturedecoding method that conforms to MPEG-4 AVC have, partly in common, thedetails of processing, such as entropy coding, inverse quantization,deblocking filtering, and motion compensated prediction. The details ofprocessing to be shared probably include use of a decoding processingunit ex902 that conforms to MPEG-4 AVC. In contrast, a dedicateddecoding processing unit ex901 is probably used for other processingunique to an aspect of the present invention. Since the aspect of thepresent invention is characterized by inverse quantization inparticular, for example, the dedicated decoding processing unit ex901 isused for inverse quantization. Otherwise, the decoding processing unitis probably shared for one of the entropy decoding, deblockingfiltering, and motion compensation, or all of the processing. Thedecoding processing unit for implementing the moving picture decodingmethod described in each of embodiments may be shared for the processingto be shared, and a dedicated decoding processing unit may be used forprocessing unique to that of MPEG-4 AVC.

Furthermore, ex1000 in FIG. 33B shows another example in that processingis partly shared. This example uses a configuration including adedicated decoding processing unit ex1001 that supports the processingunique to an aspect of the present invention, a dedicated decodingprocessing unit ex1002 that supports the processing unique to anotherconventional standard, and a decoding processing unit ex1003 thatsupports processing to be shared between the moving picture decodingmethod according to the aspect of the present invention and theconventional moving picture decoding method. Here, the dedicateddecoding processing units ex1001 and ex1002 are not necessarilyspecialized for the processing according to the aspect of the presentinvention and the processing of the conventional standard, respectively,and may be the ones capable of implementing general processing.Furthermore, the configuration of the present embodiment can beimplemented by the LSI ex500.

As such, reducing the scale of the circuit of an LSI and reducing thecost are possible by sharing the decoding processing unit for theprocessing to be shared between the moving picture decoding methodaccording to the aspect of the present invention and the moving picturedecoding method in conformity with the conventional standard.

Although the image coding apparatus and the image decoding apparatusaccording to one or more aspects of the inventive concepts have beendescribed above, the herein disclosed subject matter is to be considereddescriptive and illustrative only. Those skilled in the art will readilyappreciate that the appended Claims are of a scope intended to cover andencompass not only the particular embodiments disclosed, but alsoequivalent structures, methods, and/or uses which are obtained by makingvarious modifications in the embodiments and by arbitrarily combiningthe structural elements in different embodiments, without materiallydeparting from the principles and spirit of the inventive concept.

INDUSTRIAL APPLICABILITY

One or more exemplary embodiments disclosed herein are applicable toimage coding methods, image decoding methods, image coding apparatuses,and image decoding apparatuses. The image coding method, the imagedecoding method, the image coding apparatus, and the image decodingapparatus consistent with one or more exemplary embodiments of thepresent disclosure can be used for information display devices andimaging devices with high resolution which include televisions, digitalvideo recorders, car navigation systems, cellular phones, digitalcameras, and digital video cameras.

REFERENCE SIGNS LIST

-   200 Video encoding apparatus-   201 Transformation unit-   202 Quantization unit-   203 Inverse quantization unit-   204 Inverse transformation unit-   205 Block memory-   206 Frame memory-   207 Intra prediction unit-   208 Inter prediction unit-   209 Entropy coding unit-   210 Frame memory control unit-   300 Video decoding apparatus-   301 Entropy decoding unit-   302 Inverse quantization unit-   303 Inverse transformation unit-   304 Block memory-   305 Frame memory-   306 Intra prediction unit-   307 Inter prediction unit-   308 Frame memory control unit

The invention claimed is:
 1. A method of decoding video comprising:parsing a plurality of buffer descriptions from a sequence parameter setof a coded video bitstream; parsing (i) a buffer description identifierwhich indicates a buffer description out of the plurality of bufferdescriptions, (ii) a plurality of buffer element identifiers, each ofthe plurality of buffer element identifiers indicating each of aplurality of buffer elements within the buffer description indicated bythe buffer description identifier, each of the plurality of bufferelements corresponding to each of a plurality of reference pictures and(iii) a plurality of picture identifiers, each of the plurality ofpicture identifiers for reassigning each of the plurality of referencepictures to be associated with each of the plurality of buffer elementswithin the buffer description indicated by the buffer descriptionidentifier; selecting only one buffer description indicated by thebuffer description identifier from the plurality of buffer descriptionsfor decoding a slice included in the coded video bitstream; parsing,from a picture parameter set, a flag which indicates whether reassigningthe plurality of reference pictures to be associated with each of theplurality of buffer elements within the selected only one bufferdescription is to be executed or not; reassigning, using the pluralityof picture identifiers, the plurality of reference pictures to beassociated with each of the plurality of buffer elements within theselected only one buffer description, all the plurality of referencepictures existing in the selected only one buffer description when theflag indicates the reassigning is to be executed; not reassigning theplurality of reference pictures to be associated with each of theplurality of buffer elements within the selected only one bufferdescription when the flag indicates that the reassigning is not to beexecuted; decoding the slice from the coded video bitstream using aslice header and the selected only one buffer description which isreassigned when the flag indicates that the reassigning is to beexecuted; and decoding the slice using the slice header and the selectedonly one buffer description which is not reassigned when the reassigningis not to be executed.